DE2446072A1 - SLIT EXPOSURE DEVICE - Google Patents

Description

Patent attorneys:

Dipl, -Ing. Tiedtke Dipl.-Chem. Bühling Dipl.-Ing. Chins

8 Munich 2

Bavariaring 4, PO Box 202403

Tel .: (089) 539653-56 Telex: 524845 tipat cable address: Germaniapatent Munich

Munich, ²⁶ ' ^Se Ft- 1974 B 6233 / case GP403

Canon Kabushiki Kaisha
Tokyo, Japan

Slit exposure device

The invention relates to a slit exposure device and in particular on a slit exposure device with a fixed original carrier and a moving optical system. In particular, the Invention to a gap exposure device with an improved drive device for the ontic system, in which two or a group of movable mirrors are moved at a speed ratio of 2: 1, and a device for connecting an energy source for exposing an original.

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There are already slit exposure devices with a fixed original carrier and a movable optical one System known and in particular various optical systems in which two movable mirrors or lenses with one Speed ratio of 2: 1 (U.S. Patents 3,330,181, 3 W 053, 3,497,298, 3,062,108 and 3 689 145).

1 of the drawings shows a conventional drive device for an optical system, in which an image of an original 2 to be copied arranged on a stationary original support 1 is formed on a photosensitive medium P running through a slot 7 by means of an optical system which is composed of Mirrors 3 and 4, a fixed lens 8 and fixed mirrors 5 and 6 consists. When the photosensitive medium moves forward in the direction shown by the arrow, the mirror 3 moves in the direction shown by the arrow at a predetermined speed with respect to the moving speed of the photosensitive medium, while the mirror 4 moves in the direction shown by the arrow half the speed of the mirror 3 is moved, whereby the slit exposure is carried out while constantly maintaining a constant length of the optical path from the original to the lens 8. When the mirrors 3 and 4 reach the end positions 3 ^f and 4 '(shown with dashed lines) starting from the exposure start positions (shown with continuous lines), they move to carry out

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tion of the next exposure back to the exposure start positions.

In this case, the optical system reciprocates, and in order to obtain a better copied image, the above-described mirrors 3 and U must be moved while strictly maintaining the 2: 1 speed ratio. The simplest method for this purpose is to use the pulley principle, as shown in FIG. As can be seen there, a wire 9, one end of which is fastened to the copying machine housing, is guided over a wheel 11 which is arranged on a carriage 10 on which the mirror 4 is located. The mirror 3 is arranged on a carriage 12, and if the other end of the wire is pulled to the right - in the drawing - by a suitable drive direction, the mirror 3 and the mirror Ί can be moved to the right while maintaining the speed ratio 2: 1 with which the desired goal is achieved. The use of this optical system in a copying machine requires its movement in the form of a reciprocating motion. Thus, the carriages 10 and 12, which have arrived at the right end in the range of motion shown in FIG. 1, can be returned to their starting positions. A return device has been proposed in which the elasticity of a spring 13 as shown in Fig. 1 is used, and another return device in which a motor is used instead of the spring 13 as a drive device.

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With the return of the optical system due to the elasticity the spring must be one that has a larger shape when the optical system has a long stroke running, and thereby the spring would take up more space in the machine and therefore the entire machine would get bigger dimensions. It also makes acceleration difficult control of a return speed due to the spring characteristics and also induces shock when the optical system is stopped at its initial position. The shocks make the optical system vibrate, and better copied images cannot be preserved until such vibrations are attenuated. Obviously the lifespan becomes of the optical system, which is generally not so rigid in nature, is adversely affected by the spring.

Further, in the return of the optical system using the motor as the driving means instead springs in the wire create a slack due to the delay in starting the motor when it starts to move The wire rotates at high speeds, and therefore the optical system cannot be moved smoothly.

A wiring method using electric cables for illuminating an original will now be explained. In a conventional copying machine in which an original support on which an original is placed is stationary, and optical There are two ways to move mirrors with a light source in a ratio of 1: 1/2 for copying

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Arranging electrical cables similar to that previously described optical system are connected. According to the first type, an electrical cable is made with a length that is equal to the length the total stroke corresponds to the movement of the optical system, attached to the moving optical system, and one that is slack due to the movement of the optical system Cable part is left hanging in a room. According to the second kind, there is a guiding rail-like organ and one in that moving optical system using electricity-receiving contact built-in. These conventional procedures bring the following problems. In the first type, the holding parts are at the opposite ends of the electrical cable subjected to severe damage as a result of the tension generated by the movement of the sagging induced by the optical system. Furthermore, the sagging cable tends to come with other parts coming into contact with the machine or getting caught in it, which not only counteracts smooth operation but also creates dangers such as damaging the insulation covering the cable. With regard to the problems encountered with the second kind, it should be noted that it is not possible, is the splint-like organ in which a large current flows, to be coated with an insulation, since current is passed through this organ when grinding, and it is not advantageous in terms of safety that a rail without a coating - according to the above Executions - located in the machine. Furthermore can Incorrect contacts between the contact and the rail organ

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be caused, and the image created is through the occurrence from sparks or circuit interruptions erratically. It also leads to heavier wear and tear on the contact troublesome maintenance such as replacing the contact, and the like.

The invention therefore provides a simple slit exposure device created, with which the above problems occurring in the known devices solved will. The device according to the invention has an improved one Drive device with which optical elements, which run at a speed ratio of 2: 1, reciprocate be moved.

In the device according to the invention, the arrangement of a power supply cable on a light source is for Illumination of a template improved.

The invention is explained in more detail below with reference to schematic drawings of exemplary embodiments.

Fig. 1 illustrates a known driving device for an optical system of a copying machine;

Figs. 2 and 3 show perspective views of a

Optical system driving device of a copying machine according to the present invention;

4 shows a perspective view of a removed 509815/1149

modified form of the device according to the invention;

Pig. 5 and 6 show views for the basic explanation of the structure of the device according to the invention with an optical system of an electrophotographic copying machine; and

Pig. Fig. 7 is a view for explaining the arrangement of the electric cable and pulleys according to FIGS. 5 and 6.

In Figs. 2 and 3 is a preferably chosen embodiment the device according to the invention applied, for example, to an electrophotographic machine, in which an electrostatic latent image is created on a photosensitive medium and then the image is transferred in powder form by a transfer material. In these figures, reference numeral 14 denotes a template and reference numeral 15 a lamp for irradiating the original. Movable mirrors, such as those explained with reference to FIG. 1, are indicated at 16 and 17, and the fixed mirrors are indicated at 18 and 19; the exposure start positions are shown in solid lines and the end positions in dashed lines. The lamp 15 and the mirror 16 are attached to the movable carriage 20, and the mirror 17 is fixed to the movable carriage 21. the Carriage 20 and 2.1 are gestalt et that they move on rails 22 and 23 from left to right - in the drawing

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can be. An objective 24 is provided which images an image on a photosensitive medium P which runs through an exposure station 25. The photosensitive medium P circulating in the direction shown by the arrow is uniformly charged by a charger 27 and is then discharged by a discharger while irradiating the image light, thereby creating the electrostatic latent image thereon. The electrostatic latent image on the photosensitive medium P is converted into a visible image in the next process stage (developer station 37) and transferred by means of a transfer charger to a transfer medium C, which is picked up in the direction shown by the arrow. An intermediate drive motor (not shown) is used to drive an optical system in the illustrated copying machine and rotates large and small-sized pulleys 29 and 30 with its output shafts. A wire 31 fastened at one end to the larger pulley 29 and wound around is passed over a pulley 32 which is fastened on the right side to the copier body and is rotatably arranged so that it is directed in the opposite direction and is attached to the carriage by means of a fixing member 33 interposed therebetween, and the wire is guided over the carriage 20 via a pulley ~ $ k on the carriage 21 and then fastened to the copying machine housing. Another wire 35, one end of which is attached to the small pulley 30 and which is attached to it to the desired extent.

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is wound is directed over a fixed pulley 3β in the opposite direction, while the other End of the wire is attached to the carriage 21. These two pulleys 29 and 30 on which the wire is wound have predetermined diameters in the ratio 1: 1/2. It can be seen that the intermittently operated drive motor can be switched in the forward or reverse direction and thereby causes a reciprocating movement of the optical system, the carriage 21 with the help of Pulley 3 ^ at half the speed of the other Slide is moved, so that the above conditions are met.

The rotation of the motor runs the optical system, which is constructed as described above, a movement from the exposure start position - in solid lines drawn - to the end position - drawn in dashed lines - to begin scanning the original 14. Synchronous to scan the original, an original image is placed in the exposure station 25 via the optical system described above photographed. When the optical system has reached the end position,

the motor changes its direction of rotation and guides the optical System to the exposure start position back, like this, in shown in solid lines.

In Fig. Ί a modified embodiment is shown. In this embodiment, the wire is guided in the same way as shown in FIGS. 2 and 3 with the exception that the

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Pulleys 29 and 30 according to FIGS. 2 and 3 are divided into two individual ones. The large pulley 29 and the small one Pulleys 30 are 1: 1/2 in diameter. With the pulleys 29 and 30 directly connected gears 38 and 39 have teeth in the same number and are with- ' each other engaged. In the structure described above, when the wire 31 is placed on the pulley 29, the mirror becomes 16 moves to the right on the carriage 20 to which the wire is attached at a speed "1", while the on the carriage 21 rotatably arranged pulley 3 ^ with the other end of the wire attached to the machine housing, is moved forward to the right at one speed of "1/2". On the other hand, another wire 35, which is connected via a spring 40 to said carriage is changed in the direction by means of the fixed pulley on the left side so that the mirror is forward can be moved by taking up the wire, whose.anderes end attached to the small pulley 30 and on this is wound, which is directly connected to the gear 38 in the left side of the drawing - is connected, with which the desired functioning is sufficiently achieved. While not shown, it should be noted that both pulleys can be of the same diameter and the number of teeth of the gears can be set in a ratio of 1: 1/2.

There have been described in the previous führunpsformen · Au, the wire and pulleys as a means of

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Use transmission of driving force of the engine; however, other arrangements are also possible, for example one Combination of chain and sprocket, a combination of a perforated belt and a toothed pulley, etc. The embodiments have been explained in application to a transfer type electrophotographic copying machine; it is however, it should be noted that these embodiments also can be used in copier machines in which an image is directly on a sheet of photosensitive paper is mapped, like electrofax machines.

From the foregoing it follows that With the invention a device is created in which the organ for transmitting the driving force for movement of the optical system is guided via the output shafts and the rotation of the output shafts two groups of optical Can move the system back and forth at a speed ratio of 2: 1. With this structure are conventional Avoids springs for moving the optical system, thereby avoiding the occurrence of the aforementioned shocks when the optical system is stopped. Therefore, there is no need for the attenuation in the continuous copying operation of vibrations of the optical system caused by the impact must be taken into account, and therefore the life of the optical system is not adversely affected. Furthermore, since the optical system reciprocates by a single drive source can be moved, there is no sagging of the wire - a sagging that occurs in cases where

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where there are two drive sources. This makes the movement of the optical system in a softer way and in the precise ratio 2: 1 with simultaneous cost reduction even at high speeds. From the previous ones It will be seen from embodiments that the present invention solves numerous problems set forth above and that with the invention a drive device for an optical system for use in a copying machine is created which has a simple structure.

The following is the method of arranging electrical cables for a light source for illumination an original in the slit exposure device according to the invention explained.

With the invention a method for the arrangement of electrical cables is used in moving Electricity using organs created, wherein one end of the cable is fixed and a change in direction of the cable by means of a rotatable member such as pulleys, the wiring being constructed so that a moving member comprising the members using electricity is arranged at the other end of the cable. With this structure, there is no unnecessary tension applied to the electric cable and no slack is created in any Position at the stroke of the moving organ. Preferably, the rotatable member described above has at least Parts with which the electric cable comes into contact

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- 13 comes and they need to be isolated.

A further advantageous embodiment of the device according to the invention is explained below with reference to the drawing. The Ausführunpsform shown is described with reference> of an optical system with a light source in a elektrophotopraphischen copying machine in which a Vorlacenträper f '': -. '.:: · 1EH t and fiin tror ^ melf ^ rnires photosensitive medium having a photoconductive layer provided . Fig. 5 shows a side view of the above-mentioned embodiment, while Fig. 6 represents a perspective view of the structure of the mirror and drive systems. In FIGS. 5 and 6, a master carrier shown hl, was placed on the template h2, wherein the Original carrier Ml. Mirrors hk , 'ίΙ5, Ί6 and * J7 and a lens system 62 are used to create the image of the original ¹ J2 on the surface on the outer periphery of a drum-drum photosensitive medium 1 * 3. It is well known that when the Mirror M with a speed of ν = 1 along a guide rail 57, the mirror ^ 5 in the same direction as the mirror M with a G speed ν = 1/2 moved. The mirrors can be driven by a wire 48 which is wound three or four times around a pulley * 19, the pulley ^ 9 being connected to a reversible motor 63 which serves as a drive source. One end of the wire 48 is changed in direction by a fixed pulley 50 and is fixed at χ on a support 51 placed on the mirror M ^{1 (} J) and then through a pulley 53

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out through which the wire is fed back, and on the fastening section 55 attached. On the other hand, when changing direction, the wire reaches its other end through a fixed pulley 56 the pulley 53, over the the wire is returned and attached to the attachment portion 56. Note the pulley 53 rotatably arranged on the carrier 52 ′ for the mirror 45 which is moved with "1/2 v" with respect to the mirror 44 moved with "1 v".

With the arrangement of the wire 48 as described above, the mirrors .44 and 45 can be precisely linear along the guide rail 57 can be moved at a speed of 1: 1/2.

A station with an illumination lamp for projecting the surface of an original will now be described, wherein electrical cables are arranged according to the invention. A current required for the lamp 5 ^ is via an electrical Cable 59 fed; the problems mentioned in the discussion of the prior art cannot be solved if the cable 59 with a simple slack between the fastening element 64 in the vicinity of the lamp and the other Fastening member 60 is connected. As a result, the cable 59 is caught in parts located in the vicinity, thus damaging the cable and making it softer Copying operation is hindered.

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According to the invention, however, that is with its one Cable 59 fastened to the fastening element SO in accordance with the preceding statements is fed back through the pulley 61, which are rotatably arranged on the support 52 for the mirror Jf5 which is to be moved at a speed of "1/21, after which the other end of the cable is attached to the fastening member 60 is attached. It is of course to be noted that the pulley 61 can be arranged coaxially with the pulley 53 or both pulleys have the same member can. Furthermore, the electric cable 59 lies in parallel before or after it is returned, and it is dimensioned so that that it has the minimum length necessary for its functioning, and that each end of the fastening elements is slidable, so that unnecessary tension is not generated, which enables the tension to be adjusted. The pulley 6l can Depending on the type and characteristics of the electrical cable 59, have a suitable diameter so that it is prevented it can be determined that an excessive bending moment occurs on the cable, with which the service life is effectively made usable.

The arrangement of the electric cable 59 and the pulley 61 will now be explained with reference to FIG. 7. It will be seen that the electrical cable may have a circular cross-section with conductors 66 covered with an insulator 65, as shown in Figure 7a, or it may have a shape with a plurality of conductors 68 covered with a sheet-like insulator 67 are layered as shown in Fig. 7b, or it may be in the form of a flat plate with a number

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of conductors 70 embedded in an insulator 69. For practical use, the electrical Cable in the form of the flat plate described above is preferred because of its resistance to bending stresses in one direction, and this cable is effective because the pulley can have a small diameter.

In the relative relationship of the diameter of the cable with a circular cross-section as shown in Fig. 7a to the minimum value of the pulley diameter, it was found in a flexible cable with a core of twisted wire, which is coated with vinyl chloride, that when the values are determined in the order of magnitude of Dp = 11 x D-, the cable can withstand repeated use without the occurrence of fatigue. Is set, therefore, D ^ 6, J ¹ mm, D- yields 7.2 mm. On the other hand, in the case of a cable with a flat plate cross-section as shown in Figs. 7b and 7c, it should be noted that, for the aforementioned reasons, the diameter of the pulley can be extremely reduced and, in addition, the use of guide flanges on the opposite sides of the pulley Can be avoided. Furthermore, the pulley can be made of insulating materials, and the bearing elements can also be made of insulating materials (such as resins), which in the event of any damage to the insulating coating of the electrical cable, a breakdown in the safety circuit, which serves as a short circuit in the electrical circuit, would be blocked without starting the machine

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keep the power supply supplying electrical leakage currents, thus avoiding danger to users.

As was explained above with reference to an optical system of a copying machine, for example with the invention created an arrangement in which one end of the electrical cable is fixed, the electrical cable is changed in its direction by a rotary member and a Wiring is arranged so that a movable member with electricity consuming members at the other end of the cable is arranged. This makes the use of rail organs in which a large current flows for the the aforementioned movable organ avoided, and furthermore is the use of a contact to receive the electricity and thus spark faults between the rail organ and the Contact, replacement of the contact, etc. avoided, so that a very effective maintenance is achieved. Since to be avoided can that the cable between the fastening member on the side of the movable member of the electrical cable and the other fastening element sags, damage occurs of the cable or troubles such as electrical leakage currents due to breakage of the insulating coating material not on. Accordingly, the invention achieves that electrical Cables can be attached in which the various problems mentioned are eliminated.

It should also be noted that the present invention do not interfere with the optical system of a copier

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is restricted; it can also be used for all devices which have reciprocating elements provided with electrical parts, and this in the field of machine tools, industrial machines, work machines, etc., and so the invention is very effective.

The invention thus creates a slit exposure device in which a pre-lap bearing is fixed and an optical system is movable. An organ for transmitting a driving force that moves an optical system can, is guided over output shafts, and the rotation of the output shafts charges two groups of the optical system reciprocate at a speed ratio of 2: 1. For attaching electrical cables there is one End of the electrical cable fixed, and the direction of the cable is changed by means of a rotary organ, and the cable guide is designed such that a movable member with electricity consuming elements is arranged at the other end is.

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Claims (7)

- 19 ' patent claims Slit exposure device having a first optical device and a second optical device, both running in the same direction at a speed ratio of 2: 1, "scanning an original and returning, characterized by a movable pulley (3 ¹ O, which is on the second optical device is arranged, two fixed rotatable pulleys (32, 36) which are arranged at the opposite ends in the direction of movement of the optical devices, a first wire (31) and a second wire (35) which are guided over the group of pulleys, a first drive pulley and a second drive pulley (29, 30) on which the first and the second wire are wound, and a drive source, wherein the first wire (31) is attached at one end to the first drive pulley (29) and on this is wound, is attached to the first optical device via a fixed pulley (32), and then via the movable pulley runs and is returned and is then attached to the housing, while the second wire (35), which is attached at one end to the second drive pulley (30), via the oppositely arranged fixed pulley (36) to the second optical Device is attached, with both drive pulleys (29, 30) in the fore and aft direction; are rotatably arranged. 5098 15/1 U 9 2. Device according to Ansoruch 1, characterized in that that the first and the second drive pulley (29, 30) are arranged coaxially. 3. Apparatus according to claim 1, characterized in that the first and the second drive pulley (29, 30) individual shafts are arranged so that they sit in the power transmission state to each other. ¹ I. Device according to claim 1 or 2, characterized in that the diameters of the first and the second drive pulley £ 9.30) have the ratio 2: 1. 5. Apparatus according to claim 1 or 3, characterized in that the first and the second drive pulley (29, 30) have a speed ratio of 2: 1 to accommodate the first and second wire. 6. Slit exposure device with a first optical device and a second optical device which both move in the same direction at a speed ratio of 2: 1, scan an original and rewind, characterized by a movable pulley rotatably disposed on the second optical device is, two rotatable fixed pulleys that are at opposite ends in the direction of movement of the optical Device are arranged, a first wire and a second wire, which are passed over the group of Pienenscheiben 509815/1149 2U6072 are, a first drive pulley and a second drive pulley, on which the first and second wires are wound, and a drive source, the first wire being the with its one end attached to the first drive pulley and wound on it, is via a stationary pulley is attached to the first optical device, after which it is guided over the movable pulley and returned and is attached to the housing, while the second wire is attached at one end to the second drive pulley is attached, is guided over the movable pulley and is returned and attached to the housing, the drive pulleys being rotatable in forward and reverse directions. 7. A method for laying electrical cables with the measures according to one of the preceding claims, characterized in that one end of the electrical. see cable and determine its direction by means of a rotating organ changes, the wiring being carried out in such a way that a movable member with an electricity consuming Element is arranged at the other end, the rotating member being movable at half the speed of the movable member is. . ·. R. The method according to claim 7, characterized in that the rotary member has sections with which the electrical Cable comes into contact, at least these sections are insulated. . · 509815/1149